Representation Information

Representation Information comes in many forms. It is whatever helps in the understandability and use of the data object i.e. the bits. The OAIS Archival Information Package schema attached to a Data Object allows one to attach Structural, Semantic and Other Representation Information. However, as described above, if the Representation applies to every object in the folder then the Representation Information may be attached to the folder, or if not there then one of the higher level folders or containers.

There are many types of Representation Information which can be usefully classified as:

• Structure Representation Information

  • The Representation Information that imparts information about the arrangement of and the organization of the parts or elements of the Data Object.

    • NOTE – For example, Structure Representation Information maps bit streams to common computer types such as characters, numbers, and pixels and aggregations of those types such as character strings and arrays.

• Semantic Representation Information

  • The Representation Information that imparts information about the arrangement of and the organization of the parts or elements of the Data Object.

    • NOTE – For example, Structure Representation Information maps bit streams to common computer types such as characters, numbers, and pixels and aggregations of those types such as character strings and arrays.

• Other Representation Information

  • A type of Representation Information which cannot easily be classified as Structure Representation Information or Semantic Representation Information. It is a type of Information Object.

  • NOTE – For example, software, algorithms, encryption, written instructions and many other things may be needed to understand the Content Data Object in ways exemplified by the Preservation Objectives, all of which therefore would be, by definition, Representation Information, yet would not obviously be either Structure Representation Information or Semantic Representation. Information defining how the Structure Representation Information and the Semantic Representation Information relate to each other, or software needed to process a database file would also be regarded as Other Representation Information.

Adding Representation Information describes the various types opf Representation Information in more detail.